Multilayer paper making machine

ABSTRACT

A combination-paper making machine comprising a Fourdrinier wire on which is formed the first layer of a multi-layer paper sheet, a looped conveying felt placed adjacent to the wire; an inverform unit comprising a second layer-making unit for forming a second layer on the first layer, and is placed over the one end of said Fourdrinier wire and the opposite end of the looped conveying felt, and preferably successive inverform layer making units for forming in turn a third and other successive layers, each of said inverform units having at the bottom part thereof a dehydration mechanism whereby the texture of said multilayer paper is formed.

ill] 3,891,501

[ June 24, 1975 MULTILAYER PAPER MAKING MACHINE [75] Inventors: TeruhikoOka; Masamichi Fujii,

both of Mihara, Japan 173] Assignee: Mitsubishi Jukogyo KabushikiKaisha, Japan 22 Filed: Feb. 23, 1973 [21] Appl. No.: 335,090

[30} Foreign Application Priority Data Feb. 29, 1972 Japan 4724l46 [52]US. Cl. 162/290; 162/133; 162/299; 162/304; 162/358 [51] Int. Cl. D21!9/00 158} Field of Search 162/132, 133. 304, 306, 162/123, 125, 129298-300. 290, 358, 206 162/207 [56] References Cited UNITED STATESPATENTS 3,671.38) 6/1972 Wuhlstrom etal. 162/306 168L193 8/1972 Nykopp162/133 X FOREIGN PATENTS OR APPLICATIONS 860021 1/1971 Canada t.162/132 Primary Examiner-S. Leon Bashore Assistant E \'aminer-Richard V.Fisher Attorney, Agent, or F irmMcGlew and Tuttle 5 7 1 ABSTRACT Acombination-paper making machine comprising a Fourdrinier wire on whichis formed the first layer of a multi-layer paper sheet, a loopedconveying felt placed adjacent to the wire; an inverform unit comprisinga second layer-making unit for forming a second layer on the firstlayer, and is placed over the one end of said Fourdrinier wire and theopposite end of the looped conveying felt, and preferably successiveinverform layer making units for forming in turn a third and othersuccessive layers, each of said inverform units having at the bottompart thereof a dehydration mechanism whereby the texture of saidmultilayer paper is formed.

6 Claims, 1 Drawing Figure MULTILAYER PAPER MAKING MACHINE BACKGROUND OFTHE INVENTION 1. Field of the Invention The apparatus of the presentinvention relates to an improved combination-paper making machine inwhich multi-layer paper is formed by putting the second and preferablyfollowing paper layers in turn over the first paper layer.

2. Prior Art Among such paper machines, one has already been proposedwhich has along the entire top thereof a travelling path of a loopedFourdrinier wire as a bottom layer, a plurality of short wire makingunits which cooperate with said wire and are positioned in turn so as toreceive paper layers successively in each layer making unit thus formingthe multilayer paper which is composed of combined paper layers. Thistype of mu]- ti-layer paper making apparatus has disadvantages ofplanning, operation, conservation and cost due to the increased wirelength and weight as the number oflayer making units increases becauseall the multi-layer making units thereof for making the first andfollowing layers are arranged in the travelling direction of the singleFourdrinier wire so as to cooperate with said wire. Moreover, thecombination-paper making machine should form the first layer which is abase of the multilayer paper, in a considerable thickness while formingan excellent texture paper. A conventional combination-paper makingmachine in which all the layer making units including the first paperlayer forming unit cooperate with a common bottom wire never meets theaforementioned requirements, because of limited length of the bottomwire and the difficulties in weighing of the first paper layer as wellas other adjustments.

OBJECTS AND SUMMARY OF THE INVENTION An object of this invention is toprovide a novel, unique combination-paper making machine or device whichdoes not have the above disadvantages of the conventional paper makingmachines.

A further object is to provide a machine according to this inventionwhich has the feature of a looped conveying felt adjacent to or in theneighborhood of the Fourdrinier wire which functions to form the firstlayer of the multi-layer paper. An inverform second layermaking unit ispositioned or laid over the adjacent end of said wire part opposite tosaid first head box means for supplying paper pulp to the Fourdrinierwire. Said inverform unit is positioned adjacent the one end of thelooped conveying felt. This inverform layer making unit cooperates withthe part of the Fourdrinier wire adjacent thereto and allows the secondpaper layer to combine with the travelling first layer formed on thesaid Fourdrinier wire. This inverform layer making unit cooperates withthe combined paper layer to lead the so formed paper layer onto the endof the looped conveying felt successively. Thus, the inverform, secondlayermaking unit serves as means for conveying the doubly combined paperlayer onto the looped felt as well as for making the second paper layer.In succession to the inverform second layer-making unit. the papermaking machine has the provision along the top running part of saidconveying felt for plural pairs of inverform making units for forming inturn and combining the third and successive paper layers, said inverformmaking units having each a dehydration mechanism at its lower part whichconstitutes a means for forming texture of the paper.

DESCRIPTION OF DRAWING The device will now be described with referenceto the drawing.

The drawing shows in schematic form a combinationpaper making machineaccording to this invention.

In the drawing, reference numeral 1 represents connectively for formingthe first layer a Fourdrinier wire, which comprises an endlessly movingforaminous belt. A looped conveying felt (2) or bottom felt (2) isarranged is adjacent to said Fourdrinier wire (1); an inverformsecond-layer forming unit 3 is laid over and joins the end of the wireFourdrinier 1 and the end of the looped conveying felt 2; means 4 areprovided for forming the third and successive layers placed along thetop reach or running part 2a of the conveying felt 2 adjacent to theinverform second layer-making unit 3', said means 4 which comprisesseveral pairs of inverform making units and bottom conveying felts forforming the third and successive layers of paper in turn. Although theinverform layer making unit for the third and successive layers is shownin the drawing with only three inverform short wire units 4a, 4b, and4c, the number of said units can be suitably increased or decreased. Inaddition to the inverform layer making part 4 of the machine for formingthe third and successive layers of paper, a low nip pressure press part20 is provided along the top reach or running part 20 of the conveyingfelt 2.

The Fourdrinier wire part 1 may be that of the usual Fourdrinier papermachine. A paper slurry is supplied over the wire 7 from the head box 6to form the first paper layer.

Over the first paper layer which is travelling together with theFourdrinier wire, the second paper layer is formed by the inverform,second paper layenmaking unit 3. This inverform second layer-making unit3 has a relatively short wire 9 running around several guide rolls inthe direction of the arrow, and is provided with a suitable dehydrationmechanism 30 at the bottom part thereof to constitute a texture-formingunit. A head box 10 is positioned adjacent to the inverform unit 3 forthe second layer on the inlet side of the texture-forming part, and thepaper pulp slurry is supplied over the first layer in the space betweenthe running parts of the upper and lower wires 9 and 7, while water isremoved upward from the paper pulp slurry (i.e. in the directionopposite to the usual downward dehydration) with formation of a doublelayer of combined paper between both of the top and bottom wires. Sincethe inverform, second layer-making unit 3 is laid over the one end ofthe foraminous wire part 1 and the one end of the conveying felt 2, thedoubly combined paper layer is taken out of the wire 7 at at the otherend through the inverform, a second layenmaking unit 3 to be transferredonto the top running part 2a of the con veying felt 2. Thus, the secondlayer-making unit 3 serves as means for transferring the second layer tothe felt 2 as well as means for forming it. Therefore, it is unnecessaryto provide an open draw system in order to transfer the paper layer fromthe wire 7 to the felt 2, resulting in an increased operation efficiencybecause of no accompanying paper breakage ascribed to the open draw.

The inverform making units 4a, 4b and 40 for the third and successivelayers are arranged in turn along the top running part 2a of the loopedconveying felt 2 are constructed in a manner similar to the inverform,second layer-making unit 3. Thus, over the combined paper layer doublyformed through the inverform layer making unit 3 and transferred ontothe top running part 2a of the conveying felt 2, the paper pulp stuffsupplied from the head box 11 for the third layer is laid in the spacebetween the bottom running part of a looped short wire of the inverform,third layer-making unit 40 and the top running part 2a of the longcontinuing, looped conveying felt 2, and then undergoes upwarddehydration by means of dehydration mechanism 31 to form triple layercombined paper. In the same manner, the fourth and fifth paper layersare combined in succession through the inverform layer making units 4band 4c and so on. Thus, the multi-layer paper having a desired numberoflayers is sent to the low nip pressure press part 5 by means of theconveying felt 2 and further dehydrated with mechanisms 32 and 33.

The low nip pressure press part 5 is provided with several pairs ofpress roll means which form a pressure nip in a pair between them, andhas an endless felt 21 travelling around a plurality of guide rolls.Said felt cooperates with the bottom, continuing conveying felt 2 withholding the multi-laycr paper of completed combination between both thefelts. The paper layer is pressed while travelling through nips of thepress roll means 20 transferring water onto the felt. This low nippressure press part is provided to get easy dehydration under high nippressure in the next step.

As described hereinbefore, the present device can achieve easy adjustingof weighing, making velocity, and texture formation of the first layer,and thereby form combined paper capable of meeting the variousrequirements, because the first layer having serious influence on thequality of the combined paper is formed through a Fourdrinier type wirepart. The second layer dehydrated upwardly through an inverform layermaking unit laid over both the rer end of the wire part and the fore endof the looped conveying felt, is formed in cooperation with theFourdrinier wire, and moved from the wire to the conveying felt,requiring no use an an open draw system for transferring the paper layerfrom the Fourdrinier wire onto the conveying felt, with improvement inoperation efficiency due to reduced paper breakage. Since the third andsuccessive layers are formed through upward dehydration by means ofplural pairs of inverform making units placed along the top reach orrunning part of a looped conveying felt quite different from theFourdrinier type wire, multilayer paper can be produced with aconsiderably short cned length of Fourdrinier wire. Hence difficultiessuch as increased weight of wire when making multi-layer paper with aFourdrinier wire alone can be avoided in this device.

What is claimed is:

1. Combination paper making machine which comprises a Fourdrinier wirecomprising an endless foraminous belt defining a paper forming path,headbox means for supplying a first paper forming slurry to one end ofsaid Fourdrinier wire, a looped conveying felt having one end adjacentthe Fourdrinier wire and the other end away from said Fourdrinier wire,at least one inverform paper layer making endless wire means extendingover and between said Fourdrinier wire and said looped conveying felt,and second headbox means adjacent to said Fourdrinier wire and beforesaid inverform paper layer making means for supplying a second paperforming slurry on top of said first paper forming slurry on saidFourdrinier wire.

2. Combination paper making machine according to claim 1, wherein atleast one additional inverform paper layer making endless wire means ispositioned over and upon said looped conveying felt and adjacnet theinverform paper layer making means extending over and between theFourdrinier wire and the looped conveying felt.

3. Combination paper making machine according to claim 2, wherein saidadditional inverform means includes means for dehydration of said paper,whereby a multilayer paper of the desired texture is produced.

4. Combination paper making machine according to claim 2, including alow nip pressure press adjacent the end of said looped conveying feltaway from said Fourdrinier wire.

5. Combination paper making machine according to claim 1. wherein saidinverform means includes means for dehydration of said paper, whereby amultilayer paper of the desired texture is produced.

6. Combination paper making machine according to claim 1, including alow nip pressure press adjacent the end of said looped conveying feltaway from said Fourdrinier wire.

1. Combination paper making machine which comprises a Fourdrinier wirecomprising an endless foraminous belt defining a paper forming path,headbox means for supplying a first paper forming slurry to one end ofsaid Fourdrinier wire, a looped conveying felt having one end adjacentthe Fourdrinier wire and the other end away from said Fourdrinier wire,at least one inverform paper layer making endless wire means extendingover and between said Fourdrinier wire and said looped conveying felt,and second headbox means adjacent to said Fourdrinier wire and beforesaid inverform paper layer making means for supplying a second paperforming slurry on top of said first paper forming slurry on saidFourdrinier wire.
 2. Combination paper making machine according to claim1, wherein at least one additional inverform paper layer making endlesswire means is positioned over and upon said looped conveying felt andadjacnet the inverform paper layer making means extending over andbetween the Fourdrinier wire and thE looped conveying felt. 3.Combination paper making machine according to claim 2, wherein saidadditional inverform means includes means for dehydration of said paper,whereby a multilayer paper of the desired texture is produced. 4.Combination paper making machine according to claim 2, including a lownip pressure press adjacent the end of said looped conveying felt awayfrom said Fourdrinier wire.
 5. Combination paper making machineaccording to claim 1, wherein said inverform means includes means fordehydration of said paper, whereby a multilayer paper of the desiredtexture is produced.
 6. Combination paper making machine according toclaim 1, including a low nip pressure press adjacent the end of saidlooped conveying felt away from said Fourdrinier wire.